When people are anesthetized, they are unable to control their jaws or tongues because the tongue is a voluntary muscle innervated by the then-somnolent brain. Tongue position in particular can be of importance during anesthesia because if it is allowed to fall backwards it can block the pharynx, impeding airflow, or it may obstruct access for intended surgical procedures on structures, such as tonsils and vocal chords, located in the pharynx or larynx.
Devices have been marketed for controlling tongue position of anesthetized subjects during surgery. These devices, known herein as oral gags, typically also have provisions for wedging open a patient's mouth for oral examination or surgical procedures. Most oral gags include a tongue-controller portion that serves both to restrain the patient's tongue during the procedure and, in some devices, to position an endotracheal tube for anesthesia. Some, such as the well-known McIvor include multiple tongue depressors in varying sizes to fit small children to adult. This requires the physician to select the appropriately sized depressor prior to surgery. Other manufacturers provide an oral gag and associated single size tongue depressor, or tongue positioning device, which either fits the subject or does not. These include the Bosworth, Tobold and Andrews depressors.
Oral gag devices are occasionally used with an endotracheal tube to permit a subject to breathe, or an anesthesiologist to ventilate the subject. Typical adult endotracheal tubes have outer diameters ranging from 10.2 to 13 millimeters, with pediatric tubes ranging from 6.2 to 11 millimeters in diameter, depending on tube length. Some sizes of laryngeal mask airways have oral tubes with diameters of 13 to 16 millimeters; for some patients, laryngeal mask airway oral tubes are sufficiently large in diameter that they cannot be used with typical existing oral gag devices because the oral gag device does not leave sufficient room for the tube. Some other prior devices may leave insufficient room for simultaneous presence of a laryngeal mask tube and surgical access to the mouth and pharynx.
Typically, a prior-art oral gag device 100 (FIG. 1 and FIG. 2) includes a rigid frame 102. Attached to the frame is typically an upper blade 104 with a smooth-sided surface for positioning at, and applying upward pressure to, the roof of a subject's mouth, and an attaching portion 110 for supporting a tongue positioning device 106. The device illustrated in FIG. 1 and FIG. 2 is not representative of any particular oral gag, it is intended to illustrate typical components and to illustrate the field of application of the device disclosed herein. Engagement between attaching portion 110 and tongue positioning device 106 is typically adjustable, by pressure applied to an engagement release 116, to allow adjustment of a displacement between the upper blade and tongue positioning device 106. The tongue positioning device 106 typically has a depressed tip 108, a vertical portion 112 with engaging notches, slots, or grooves for engagement with an engagement mechanism associated with engagement release 116, and a handle tab 114. In use, the upper blade 104 and tongue positioning 106 devices are placed within a subject's mouth, the engagement release 116 is pressed, and the handle tab 114 is pulled to tighten the tongue positioning device against the subject's lower jaw and tongue. The engagement release is then released to retain position with the subject's mouth open. Typical prior tongue positioning devices 106 are unitary components that are not adjustable. Particular prior-art oral gag devices may have tongue positioning devices 106 that may be easily interchanged with one having a different length, thereby better accommodating subjects having different mouth sizes.